Introducing the brain: how complexification works (Introduction)

by David Turell , Monday, August 12, 2024, 19:33 (101 days ago) @ David Turell

The latest study:

https://medicalxpress.com/news/2024-08-neural-brain.html

"Our brain interprets visual information by combining what we see with what we already know. A study published in the journal Neuron, by researchers at the Champalimaud Foundation, reveals a mechanism for learning and storing this existing knowledge about the world.

"They found that neurons are wired to connect seemingly unrelated concepts. This wiring may be crucial for enhancing the brain's ability to predict what we see based on past experiences, and brings us a step closer to understanding how this process goes awry in mental health disorders. (my bold)

"How do we learn to make sense of our environment? Over time, our brain builds a hierarchy of knowledge, with higher-order concepts linked to the lower-order features that comprise them. For instance, we learn that cabinets contain drawers and that Dalmatian dogs have black-and-white patches, and not vice versa.

"This interconnected framework shapes our expectations and perception of the world, allowing us to identify what we see based on context and experience.

***

"The brain's visual system consists of a network of areas that work together, with lower areas handling simple details (e.g. small regions of space, colors, edges) and higher areas representing more complex concepts (e.g. larger regions of space, animals, faces).

"Cells in higher areas send "feedback" connections to lower areas, putting them in a position to learn and embed real-world relationships shaped by experience.

***

"'To do this, we examined the effects of visual experience on feedback projections to a lower visual area called V1 in mice. We raised two groups of mice differently: one in a normal environment with regular light exposure, and the other in darkness. We then observed how the feedback connections, and cells they target in V1, responded to different regions of the visual field."

"In mice raised in darkness, the feedback connections and V1 cells directly below them both represented the same areas of visual space.

First author Radhika Rajan says, "It was amazing to see how well the spatial representations of higher and lower areas matched up in the dark-reared mice. This suggests that the brain has an inherent, genetic blueprint for organizing these spatially aligned connections, independent of visual input."

"However, in normally-reared mice, these connections were less precisely matched, and more feedback inputs conveyed information from surrounding areas of the visual field.

***

"...the team discovered that in normally-reared mice, deep-layer feedback inputs to V1 become organized according to the patterns they "prefer" to see, such as vertical or horizontal lines. "For instance," Dias says, "inputs that prefer vertical lines avoid sending surrounding information to areas located along the vertical direction. In contrast, we found no such bias in connectivity in dark-reared mice."

""This suggests that visual experience plays a crucial role in fine-tuning feedback connections and shaping the spatial information transmitted from higher to lower visual areas," notes Petreanu."

Comment: obviously all levels of brains in size or complexity have the capacity to coordinate into new networks of understanding. It is not just our brain that has complexification ability. I asssume it is a mechanism going all the way back to Trilobites.